Telegraphy



Patented May 12, 1925.

UNITED STATES- WILLIAM M. BRUCE, JR, 0F SPRINGFIELD, OHIO.

IELEGRAPHY.

Application filed October 4, 1919. Serial No. 328,525.

To aZZ whom it may concern:

Be it known that I, WILLIAM M. BRUCE, J12, a citizen of the United States, residing at Springfield, in the county of Clark and State of Ohio, have invented certain new and useful Improvements in Telegraphy, of which the following is a specification.

My invention relates to improvements in telegraphy and more particularly to systems and apparatus for receiving signals over lines of high retardation such as submarine cables.

The invention has for its ob ect the 1mprovement of systems and apparatus of this r character when a radio-electric element is employed for varying the resistance in a local circuit as a part of the receiving or relaying apparatus andfurther for simplitying and stabilizing the apparatus and its operation in work of this character.v

The difiiculties in the use of selenium or similar radio-electric elements has been recognized and while many different systems and devices have been employed with more or less favorable results, such apparatus has been more or less complicated and has required such delicacy of adjustment as to make them more or less impracticable for commercial work.

In my improved system I employ two separate cells of radio-active material such as selenium in connection with the usual reflecting galvanometer and these cells I arrange separate and distinct each in a separate circuit with the primary of a transformer and while I place these cells at a slight distance apart they are so arranged that neither of the cells are normally illuminated as I em loy a narrow beam of light from the eflecting galvanometer which in-itsnormal position stands in a new tral position between the cells the beam of light being proportioned to the space between the cells so that said space need be but slightly, if any, larger than said beam in such a way that a very slight movement of the mirror in either direction will illuminate one of the cells or the other. From the secondary of each of these transformers I provide a circuit which includes a polarized relay of any well .known and suitable type .which will respond to impulses of current and these respective rela s are used to make and break battery circuits employing any suitable type of relay which will control the signalling apparatus such as a recorder, a sounder or a repeating apparatus.

As the invention herein set forth is designed especially for use with what is known as recorder type of signals that is one in which a current of one polarity represents a dot and that of another represents a dash, I have shown the apparatus controlled by the polarized relays to be particularly adapted for this class of signals and the local relays controlled by the polarized relays are shown as repeating relays repeat ing the signals into another cable. This, of course, can be used in many ways, either connected directly to a recorder so that one relay will move the recorder in one direction and the other relay move the recorder in the other direction or they could be arranged tocontrol Sounders of different character so that one sounder would represent a dot and the other a dash in a well known manner.

Inasmuch as all the apparatus which I employ is or may be of a standard type, I

have illustrated this invention only in dia gram shown in the figure which is a diagrammatic View of a receiving and a repeating apparatus embodying my invention.

In the said drawings 1 represents a line of high retardation such as a submarine cable to which is connected in the usual Way a reflecting galvanometer, 2, so as to receive the current impulses of opposite polarity from the cable 1 and cause its oil to move in one direction or the other as the impulse is positive or negative. 3. is a lampof a proper type operating through lensese, 5

and 6 so as to direct the rays of light on.

the mirror 7 of the galvanometer from which it is reflected onto a neutral zone 8' arranged between cells 9 and 10 of a radioelectric element, such as selenium 11. and 12 are induction coils or transformers, the primary coils 11 and 12 of which are" connected respectively to the selenium cells 9 and 10 through batteries 11 and 12 by wires. I

a, b, and c, and a 7) and 0 respectively. The secondary coils 11 and 12 of the transformers 11 and 12 are connected directly to polar relays 13 and 14 and these transformers are so constructed that the illumination of either one of the selenium cells will cause an increase or decrease of current through will in turn induce a current in the secondary coils and operate' the relay connected thereto. I have discovered that by arranging these transformers in this simple and direct manner and providing the proper values that I secure a perfect response in the relays 13 and 14 to the movements of the galvanometer as influenced by the incoming signals on the cable and this response is so perfect that these polar relays will repeat these impulses through any well constructed andproperly adapted receiving apparatus without the addition of correction coils, locking apparatus or similar de vices which are usually employed and which complicate both the operation and the ad justment of the apparatus. Inthe drawings I have shown these polar relays each as provided with a tongue 13 and 1 1 operating in connection with contacts 15 and 15 and 16 and-16; the contacts 15 and 16 being terminals in an electric circuit and those 15 and 16 being merely stop contacts having no other function in the present case than to stop the tongues 13 and 14s in their reverse movements. The contacts 15 and 16 are connected by wires 19 and 20 to relays 17 and 18 which relays are in turn connected by wires 21 and 22 through battery 23 and by wires 24 and 25 to the respective ton ues 13" and 14* of the relays 13 and 1 1 so that as either of the said relays 13 and 14 is actuated in its forward direction it closes the circuit of one'of the relays 17 and 18 causing the said relay to operate and thus reproduce the signal either directly or through some subsequent apparatus as indicated on the drawings. I have shown these relays 17 and 18 provided with tongues 17 and 18*, the tongue 17 of relay 17 is connected by wire 26 to ground and the tongue 18 of relay 18 is connected by wire 27 to the cable. The respective contacts 17 and 17 and 18 and 18 of these relays are connected by wires 28 and 29 to opposite sides of a repeating battery 30 so that when the relay 17 is operated a negative impulse from the battery 30 will be applied to the cable and when the relay 18 is operated a positive impulse will be applied to the battery or vice versa and thus the incoming impulses or signals on the cable 1 will be repeated through wires 26 and 27 to an other cable 31 or any other circuit.

It is obvious that instead of the relays 17 and 18 operating as repeaters to supply impulses of current to other circuits they might be made to operate other signalling apparatus such as sounders recorders or printing mechanism from which the signals could be read.

By using the circuits herein described in which each selenium cell 18 normally unillaminated and said cell in circuit with the primary of its own transformer with a separate translating circuit, the relay connected to the secondaries of the respective transformers may be of uniform type or construction and need be operated in one direction only and moved in the opposite direction by mechanical movement each as a spring and while the increase and the decrease of the current in the primary will produce a reversal in the secondary of the transformer which will assist the polarized relay in circuit with the secondary to its marking and spacing position, the contact is on one side only and therefore it is in no sense a marginal operation but positive in character.

.Vhere it is desired to use the recorder type of signals in block formation which is customary now where rapid signalling is desired I have found it desirable to use the secondary of the transformer of very low resistance preferably lower than the resistance of the movable coil of the polarized relay which is in series therewith and in order to obtain the necessary volume of current even at the expense of the voltage I use a high resistance as well as a high impedance in the primary coi-l, the result of this low resistance of the secondary is to dampen the effect of the polar relay and make it hold up for a considerable period of time when the illumination of the cell controlliiig the primary of that transformer continues for a given length of time, in fact, with a primary of four thousand turns and approximately eight hundred ohms and a secondary of two thousand turns and approximately one hundred and seven'syefive ohms resistance I have been able to hold up the polarized relay for a period of five or six seconds or enough to make a dash on an ordinary writer of five or six feet in length. i 'Another result from using the closely spaced selenium cells, neither one of which is normally illuminated, and reflecting the narrow beam of light on one or the other by the impulses representing the dots or the dashes I am able to do away with the usual local correction necessary in relay translation since while the ray of light may not by continuous operation on one cell only for a period of time continue to completely cover that cell, yet its action upon the cell will be sufficient, by the use of the divided transformers, to completely operate the polarized relay through the secondary of -that transformer for a very considerable longer period of time thanwould ever occur in actual practice. And inasmuch as this arrangement is capable of very high speed and the higher the speed the shorter the time required in transmitting any particuarea is required in each circuit and but an extremely slight movement of the galva' nometer in either direction is sufficient to translate impulses of opposite polarity through the magnifying circuits which not only permits very high speed but permits the operation of the galvanometer by the most minute current, thus making it possible to receive and magnify extremely delicate or feeble signals.

As showing the possibility of the system I may say that I have actually operated this apparatus at a speed of 600 letters per minute with a current through the galvanonieter of live micro (.000005) ampere s Having thus described my invention, I claim 1. In a system such. as described in which current impulses of opposite polarity are adapted to operate a galvanometer in opposite directions in connection with a narrow beam of light focused on the mirror of said galvanometer so that in its neutral position it stands between two selenium resistance elements separated by a space substantially equal to the breadth of the'light beam so that as the galvanometer is moved in one direction one element is illuminated and when moved in the other direction the other element is illuminated, two separate and distinct circuits from said elements each of which includes a source of electric energy and the primary of a transformer, the secondaries of said transformers being each .in circuit with a separate polarized relay and separate circuits each with its own 'translatingdevice controlled by the respective relays so that as the galvanometer 'is moved in either direction the change in either selenium element by its illumination will, through its transformer operate its 'own relay and translating device for the purpose specified. I

2. In a system such as described where current impulses of opposite polarity are used to indicate dots or dashes and to illuminate separate elements of radio-electro resistance which elements are each in circuit with a battery and the primary of a transformer, a polar relay in circuit with the secondary of a transformer, said transformer being constructed with a primary of comparatively high resistance and a secondary of comparatively low resistance, the resistance of the secondarybeing such that the suspended coil of the'polar relay in circuit therewith is critically dampened and maintained in its operated position for a considerable period during the illumination of said cells.

In testimony whereof, I have hereunto set my hand this thirtieth day of September, 1919. i

WILLIAM i1. BRUCE, JR;

lVitness:

CHAS. I. WELCI-L 

